Prohalecites and Hulettia

Prohalecites porroi (Bellott 1857, Tintori 1990, MCSNIO P 348, Middle Triassic; 4cm) is a late surviving basal bony ray-fin fish (Actinopterygia, Osteichthyes). This fish is traditionally considered the oldest known teleostomorph (teleost).

No trace of scales is preserved in any specimen. No neurocranial material is preserved. Tintori left Prohalecites as a Neopterygian incertae sedis, "because its characters do not perfectly fit in any of these cited groups." Hemichordacentra are present. The preopercular is so slender it is rodlike.

Hulettia americana (Eastman 1899, Early Jurassic, NMNH 4788a, 10cm, up to 19cm). Traditionally considered a member of tlhe Palaeonisciformes, Hulettia is a longer specimen transitional from Prohalecites and Ichthyokentema to the extant, long-bodied Narcetes on one branch of the LRT, and Lepidogalaxias on the other branch.

Arratia G and Tintori A 1999. The caudal skeleton of the Triassic actinopterygian †Prohalecites and its phylogenetic position, p. 121–142. In: Mesozoic Fishes 2—Systematics and Fossil Record. G. Arratia and H.-P. Schultze (eds.). Verlag Dr. F. Pfeil, München.

Arratia G 2015. Complexities of early Teleostei and the evolution of particular morphological structures through time. Copeia 103(4):999–1025.

Bellotti C 1857. Descizione di alcune nuove specie di pesci fossili di Perledo e di altre localtta lombarde. 419–432. In Sopani A (ed) Studi geologici sulla Lomabardia. Editore Turati, Milano.

Chevrinais M, Sire, J-Y and Cloutier R 2017. From body scale ontogeny to species ontogeny: Histological and morphological assessment of the Late Devonian acanthodian Triazeugacanthus affinis from Miguasha, Canada. PLOS ONE. 12 (4): e0174655. Bibcode:2017PLoSO..1274655C. doi:10.1371/journal.pone.0174655

Eastman CR 1899. Jurassic fishes from Black Hills of South Dakota. Geological Society America Bulletin 10:397-408.

Fujiwara Y et al. 2021. Discovery of a colossal slickhead (Alepocephaliformes: Alepocephalidae): an active-swimming top predator in the deep waters of Suruga Bay,
Japan. Nature Scientific Reports 11:2490.

Tintori A 1990. The actinopterygian fish Prohalecites from the Triassic of northern Italy. Palaeontology 33:155–174.

wiki/Prohalecites
wiki/Hulettia

Actinista

Latimeria

Lepisosteiformes

Gavinia

Lepisosteus

Robustichthys

Prionotus

Amiiformes

Prohalecites

Amia